Just cause its 5 miles long doesn't mean they'll use it all, doubt any car would last going that distance at full throttle. Its been used plenty of times by top gear so there's bound to be sections which are pretty good and useable.
Steve has a thing about running more than 1 mile. You wont change that.
On a personal level Mark has set a limit of how long we can be at 100% WOT so im limited to sub 2 miles at my Power level. My car wont be finished to take part anyway but I am interested in the distance allowed.